Middle ear effusion, or serious otitis media (SOM), is a very common conditon in children and, if not treated in time, may cause irrevocable setbacks in the child's development. However, its epidemiology, etiologies, and pathogenesis are not yet clear. We are planning to have a three-day symposium and a one-day research conference in order to gather state of knowledge on basic research in middle ear effusions, to determine the scientific rationale for the diagnosis and management of this condition, and to delineate and recommend the future direction in research concerning this problem.